Long Durational Natural Phenomenon

Existence of Devil’s Tower

Duration: 225-195 Million years

Devil's Tower is an igneous intrusion or laccolith in the Bear Lodge Mountains in northeastern Wyoming above the Belle Fourche River. It rises 1,267 feet (386 meters) above the surrounding terrain and the summit is 5,114 feet (1,559 meters) above sea level. The oldest sedimentary rocks which make up most of the surrounding landscape of Devil's Tower were laid down in a shallow sea during the Triassic period 225 to 195 million years ago.

Geologists Carpenter and Russell studied Devil's Tower in the late 19th century and came to the conclusion that it was formed by an igneous intrusion, a theory that is still believed to be true today. Some scientists are convinced the tower is all that remains of what once was a large explosive volcano.